Net Energy Metering FAQs

What is Net Energy Metering (NEM)?

Customers who generate their own electricity with renewable energy sources can interconnect with the electric grid. A special net-capable meter measures the energy a customer uses off the grid and the excess generation the renewable system provides onto the grid, and calculates the difference or “net.”

What is Green Power Connection?

Green Power Connection™ (GPC) is our process for facilitating small generator and NEM interconnection requests. Our dedicated team of consultants and account coordinators manage the customer’s experience – from processing applications to resolving issues – for residential and smaller commercial interconnection projects.

What is a net-capable meter?

A net-capable meter measures energy that flows in both directions between the customer-generator and the electric grid.

What technologies qualify for net energy metering?

In Maryland, small generator technologies that qualify for interconnection with our system include solar (photovoltaic or “PV”), wind, biomass, fuel cells, qualifying closed circuit hydro-electric, and micro-combined heat and power (up to 30 kW). CHP or cogeneration systems can be interconnected but not net-metered. See our GPC website for more details.

Do I have to interconnect my generator system to the grid?

Most customers install renewable generator systems to reduce their use of utility-supplied electricity. For these behind-the-meter systems to be able to draw energy off the grid when needed, the system must be interconnected to a utility-supplied, net-capable meter. You must apply for this interconnection.

Does the net-capable meter measure total generation?

No. Generation occurs on the customer side of the meter. Any energy generated is first fed inside the premise for use by the appliances, electronics, lights, etc. The meter measures only the excess energy that is fed onto the grid.

How does the meter show when energy is fed or received?

A net energy meter has dashes under the display that move in the direction of the energy flow. When the dashes move from left to right, energy is flowing from the grid to the customer’s premise. When the dashes move from right to left, energy is flowing from the customer to the grid.

How long does the interconnection application process take?

From the day you or your contractor first submits a complete application to the day Delmarva Power issues your final Authorization to Operate, including the time it takes your contractor to install the solar generating system, the interconnection application process in Maryland takes approximately 77 business days. Click here to download a printable PDF of the application timeline.

What if I have questions while completing the application?

If you have questions about your application, you can ask them at any time directly in the portal by clicking on the question mark icon in the left navigation.

How do I approve my application?

Delmarva Power will send you an email when your application is ready for your review and approval. This handy Customer Approval of NEM Application guide describes the steps. You can begin your review and approval by clicking on the link in Delmarva Power’s email to you, or by entering the portal.

How is my application fee determined?

Fees are established by the Maryland Public Service Commission, and vary according to the generator system’s nameplate capacity. Our online interconnection application system automatically calculates any required fees, based on jurisdiction, system size and application level. See our fees in Maryland.

When do I pay my application fee?

After your interconnection application has been entered into the online portal, the system automatically determines if an application fee is required and calculates the required fee, based on the jurisdiction, system size, and application level. The online system automatically creates and emails an invoice to the contractor or customer. This fee invoice must be paid before Delmarva Power can issue the Authorization to Operate your renewable generator system.

How do I pay my application fee?

The contractor pays the invoice either by credit card or bank transfer through Speedpay or by mailing in a check with the invoice.

Why could my interconnection application be delayed or denied?

Applications are delayed if required information is incomplete or missing, or documents are unsigned. In some regions, our utility may not have an open circuit, making net metering interconnection unavailable. For more details, contact our GPC team.

How is the size of the renewable system determined?

Add up the total energy consumption (in kWh) as shown on your last 12 Delmarva Power bills. Divide that sum by 1,200. Multiply that number by 2. The result is the maximum inverter nameplate rating you can install. We use the formula (12-month kWh usage / 1,200) x 2 = maximum kW inverter rating, to comply with state rules, meet all or part of your electrical needs, and follow our regulatory requirements.

What is the maximum size of a small generator system I can install?

Customers who install a renewable generating system and intend to net meter can offset all or part of the energy they use from Delmarva Power. In Maryland, the system capacity can be up to 200% of your 12-month historical energy consumption.

How can I see how much energy my system generates?

The installer of your renewable system can provide details on obtaining a generation monitoring device compatible with your system.

What standards does Delmarva Power apply when approving inverters and system components for interconnection?

Institute of Electrical and Electronics Engineers (IEEE) Standard 1547 provides the criteria and requirements for interconnecting small generator equipment to the electric grid. Underwriters Laboratory (UL) Standard 1741 sets the requirements for the inverters and charge controllers used in photovoltaic (PV) power systems. In most cases, inverters that comply with IEEE 1547 and UL 1741 will be acceptable for interconnection. The equipment on the Acceptable Inverters List has been accepted for use in other small generator interconnection project requests.

Will my system generate power during a utility power outage?

For safety reasons, the system's inverter tied to the grid will shut down automatically with an outage. The inverter converts direct current (DC) power from the renewable generator into alternating current (AC) power used at your premise. Only systems designed to operate independently during an outage will be able to operate. A system designed in this fashion must be clearly identified on the interconnection application and agreement. A single-line diagram showing the equipment and controls necessary to operate safely when isolated must accompany the application.

If I have a new construction project that will incorporate a small generator system, can I interconnect?

Yes. For a facility that is under construction and requires electricity, you will need to set up electric service prior to installing the generation system. Without any historical energy consumption data, the interconnection application will require a proposed energy usage calculator.

I want to install a large generation facility and sell power directly to the grid. Do I work with the GPC team?

No. Another department within Delmarva Power administers these large wholesale power purchase agreements. The GPC team will be glad to refer you to that department.

Are customers with third-party energy suppliers eligible?

Yes.

NEM Billing FAQs

How is excess generation shown on my utility bill?

Customers in Maryland see negative energy consumption in the Details of Your Charges section of the bill, showing the excess generation carryover history. The excess is carried over month to month until used or until the customer’s anniversary pay out.

Why does my bill still show charges if I had excess generation credits?

Customer service charges apply to all bills, regardless of energy charges or excess generation credits. If the service charges are more than the generation credits your account will show a balance due.

What is a Solar Renewable Energy Credit (SREC)?

An SREC is equivalent to one megawatt-hour (MWh) of electricity derived from an
eligible solar resource. Electricity suppliers must purchase SRECs in order to
meet compliance obligations under the law. For more information, visit energy.gov.

Other FAQs

Are there other factors to consider?

Yes. Electric generation from solar sources can fluctuate as a result of several factors — clouds, darkness, and dirty panels all limit generation. Your renewable system may not generate enough energy to meet all of your electrical needs. Prior to installation, understand how your system will operate under varying conditions, and how these conditions can impact your utility bill.

Can I operate my generation facility prior to receiving the final written Authorization to Operate?

No. The Maryland Public Service Commission prohibits the interconnection of generation facilities to the electric grid without Delmarva Power's written approval. Operating an unauthorized small generator system tied to Delmarva Power's grid can:

Endanger Delmarva Power workers, who will not have a record of the system

Pose a safety risk to the customer, system components, facility, and general public

Cause voltage overload problems on the grid, preventing safe and reliable electric service

Lead to a cease-and-desist notification

Lead to disconnection of electric service

Can you recommend a reputable installer?

No. We recommend you research and consult with an installer or contractor by using publically available resources. If you decide to work with a contractor, it is your responsibility to ensure they use the appropriate forms, fees, and documentation throughout the interconnection process.

As public concern about ecosystems, changing habitats, pollution and land management continues to grow, we remain committed to sustainable conservation and restoration initiatives as an integral part of our business operations.
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